Method for manufacturing semiconductor device

ABSTRACT

A method for manufacturing a semiconductor device. A photolithographic coating, including a first film, a photolithographic film, and a second film, is formed on the to-be-connected structure. Refractive indexes of the first film and the second film are smaller than 1. The photolithographic coating is exposed to a light having a first wavelength, to image the to-be-connected structure to a first region of the photolithographic film. The photolithographic coating is exposed to a light having a second wavelength through a mask, to image the mask to a second region of the photolithographic film. A region in which the first region and the second region overlap serves as a connection region corresponding to the to-be-connected structure, and thereby self-alignment between a layer of the to-be-connected structure and a layer where a contact hole is arranged is implemented.

The present application claims priority to Chinese Patent ApplicationNo. CN202111228704.0, titled “METHOD FOR MANUFACTURING SEMICONDUCTORDEVICE”, filed on Oct. 21, 2021 with the China National IntellectualProperty Administration, which is incorporated herein by reference inits entirety.

FIELD

The present disclosure relates to the field of semiconductor devices,and in particular to a method for manufacturing a semiconductor device.

BACKGROUND

It is particularly important to ensure alignment between differentlayers when manufacturing a semiconductor device. A large error in thealignment may result in a failure in electrical connection betweendifferent layers, thereby deteriorating performances of the manufacturedsemiconductor device. Self-alignment techniques are important means toimplement the alignment between different layers. At present, suchtechniques are commonly applied to alignment between a metal layer andan interconnection layer.

A limitation of the self-alignment techniques results in a large errorwhen manufacturing semiconductor devices, for example, when forming acontact hole, which reduces a yield of a manufactured semiconductor.

Therefore, it is urgent to provide a method for manufacturing asemiconductor, which can improve accuracy of the alignment betweendifferent layers and reduce an error in the alignment.

SUMMARY

In view of the above, a method for manufacturing a semiconductor deviceis provided according to embodiments of the present disclosure, in orderto improve accuracy of alignment between different layers and reduce anerror in the alignment.

Following technical solutions are provided according to embodiments ofthe present disclosure to achieve the above objective.

A method for manufacturing a semiconductor device is provided accordingto an embodiment of the present disclosure. The semiconductor deviceincludes a substrate and a to-be-connected structure disposed on a sideof the substrate. The method includes:

-   -   forming a photolithographic coating on the to-be-connected        structure, where the photolithographic coating includes a first        film, a photolithographic film, and a second film which are        stacked in the above-listed sequence, and refractive indexes of        the first film and the second film are smaller than 1:    -   exposing the photolithographic coating to a light having a first        wavelength, to image the to-be-connected structure to a first        region of the photolithographic film; and    -   exposing the photolithographic coating to a light having a        second wavelength through a mask, to image a pattern of the mask        to a second region of the photolithographic film, where a region        in which the first region and the second region overlap serves        as a connection region corresponding to the to-be-connected        structure.

In an embodiment, a thickness of the photolithographic coating ispredetermined based on light intensity, which in the photolithographicfilm when the photolithographic coating is exposed to the light havingthe first wavelength.

In an embodiment, before forming the photolithographic coating on theto-be-connected structure, the method further includes: forming adielectric layer on the to-be-connected structure, where the dielectriclayer is disposed between the to-be-connected structure and thephotolithographic coating.

After exposing the photolithographic coating to the light having thesecond wavelength through the mask, the method further includes: etchingthe dielectric layer corresponding to the connection region through thephotolithographic film, to obtain a contact hole running through thedielectric layer, where the to-be-connected structure is exposed by thecontact hole.

In an embodiment, before etching the dielectric layer corresponding tothe connection region through the photolithographic film, the methodfurther includes: removing the second film.

In an embodiment, after etching the dielectric layer corresponding tothe connection region through the photolithographic film to obtain thecontact hole running through the dielectric layer, the method furtherincludes: filling the contact hole with metal, to form a metal contact.The metal contact is connected with the to-be-connected structure.

In an embodiment, the photolithographic film is made of a photoresist,and the first film and the second film are made of metal materials.

In an embodiment, the light having the first wavelength is a visiblelight or an ultraviolet light, and the light having the secondwavelength is another ultraviolet light.

In an embodiment, the first wavelength is 633 nm, 532 nm, or 365 nm, andthe second wavelength is 365 nm, 248 nm, or 193 nm.

In an embodiment, the to-be-connected structure is at least one of: agate structure, a source structure, or a drain structure.

In an embodiment, a feature size of the pattern of the mask is largerthan a feature size of the to-be-connected structure.

The method for manufacturing the semiconductor device is providedaccording to embodiments of the present disclosure. The semiconductordevice includes the substrate and the to-be-connected structure disposedon the side of the substrate. The photolithographic coating is formed onthe to-be-connected structure. The photolithographic coating includesthe first film, the photolithographic film, and the second film, whichare stacked in the above-listed sequence. The refractive indexes of thefirst film and the second film are smaller than 1, so that thephotolithographic coating forms an optical structure with a highreflection coefficient. Then, the photolithographic coating is exposedto the light having the first wavelength. The to-be-connected structureis reflected in the photolithographic coating, and hence serves as amask and is imaged to the first region of the photolithographic film.Afterwards, the photolithographic coating is exposed to the light havingthe second wavelength through the mask. The mask is imaged to the secondregion of the photolithographic film. The region in which the firstregion and the second region overlap serves as the connection regioncorresponding to the to-be-connected structure. That is, positions atthe to-be-connected structure are imaged into the first region of thephotolithographic film after the exposure with the light having thefirst wavelength, and the pattern of the mask is imaged to the secondregion of the photolithographic film after the exposure with the lighthaving the second wavelength. The region in which the first regionoverlaps the second region corresponds to the to-be-connected structure,and thereby self-alignment between a layer of the to-be-connectedstructure and a layer where the contact hole is arranged is implemented.Only the region in which the imaging regions of the two exposuresoverlap corresponds to the to-be-connected structure, which improvesaccuracy of the alignment between different layers and reduces the errorof the alignment.

BRIEF DESCRIPTION OF THE DRAWINGS

For clearer illustration of the technical solutions according toembodiments of the present disclosure or conventional techniques,hereinafter briefly described are the drawings to be applied inembodiments of the present disclosure or conventional techniques.Apparently, the drawings in the following descriptions are only someembodiments of the present disclosure, and other drawings may beobtained by those skilled in the art based on the provided drawingswithout creative efforts.

FIG. 1 is a flowchart of a method for manufacturing a semiconductordevice according to an embodiment of the present disclosure.

FIG. 2 is a top view of a structure of a semiconductor device accordingto an embodiment of the present disclosure.

FIG. 3 is a cross-sectional view of a semiconductor device as shown inFIG. 2 along a direction indicated by AA.

FIG. 4 and FIG. 5 are schematic structural diagrams of a semiconductordevice manufactured through a method according to an embodiment of thepresent disclosure.

FIG. 6 is a schematic diagram showing correspondence between a thicknessof a photolithographic film and intensity of a light according to anembodiment of the present disclosure.

FIG. 7 is a schematic structural diagram of a semiconductor devicemanufactured through a method according to an embodiment of the presentdisclosure.

FIG. 8 is a top view of a semiconductor device and a mask according toan embodiment of the present disclosure.

FIG. 9 to FIG. 11 are schematic structural diagrams of a semiconductordevice manufactured with a method according to an embodiment of thepresent disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

In order to make the above objectives, features and advantages of thepresent disclosure obvious and understandable, hereinafter embodimentsof the present disclosure are described in detail in combination withthe drawings.

Many details are set forth in following description to facilitate a fullunderstanding of the present disclosure. The present disclosure mayfurther be implemented in other ways different from those describedherein. Those skilled in the art may deduct by analogy without violatinga core concept of the present disclosure. Therefore, the presentdisclosure is not limited to embodiments disclosed below.

The present disclosure is described in detail in conjunction with theschematic diagrams. When embodiments of the present disclosure aredescribed in detail, a part of a device may not be enlarged according toa general scale in a sectional view showing a structure of the device,in order to facilitate illustration. The schematic diagrams are onlyexemplary, which should not be construed as limitation on the protectionscope of the present disclosure. In addition, dimensions in athree-dimensional space, for example, including a length, a width, and adepth should be set in actual manufacture.

At present, self-alignment techniques are important means to implementalignment between different layers. The self-alignment is commonlyutilized to implement alignment between a metal layer and aninterconnection layer.

After a source, a drain, or a gate of a semiconductor device is formed,there is no effective self-alignment technique capable to align acontact hole, which is configured to connect the source, the drain, orthe gate with outside (lead the source, the drain, or the gate out),accurately with the source, the drain, or the gate when forming thecontact hole.

In order to address the above issue, a method for manufacturing asemiconductor device is provided according to an embodiment of thepresent disclosure. The semiconductor device includes a substrate and ato-be-connected structure disposed on a side of the substrate. Aphotolithographic coating is formed on the to-be-connected structure.The photolithographic coating includes a first film, a photolithographicfilm, and a second film, which are stacked in the above-listed sequence.Refractive indexes of the first film and the second film are smallerthan 1, so that the photolithographic coating forms an optical structurewith a high reflection coefficient. Then, the photolithographic coatingis exposed to a light having a first wavelength. The to-be-connectedstructure is reflected in the photolithographic coating, and henceserves as a mask and is imaged to a first region of thephotolithographic film. Afterwards, the photolithographic coating isexposed to a light having a second wavelength through a mask. The maskis imaged to a second region of the photolithographic film. A region inwhich the first region and the second region overlap serves as aconnection region corresponding to the to-be-connected structure. Thatis, positions at the to-be-connected structure are imaged into the firstregion of the photolithographic film after the exposure with the lighthaving the first wavelength, and the pattern of the mask is imaged tothe second region of the photolithographic film after the exposure withthe light having the second wavelength. The region in which the firstregion overlaps the second region corresponds to the to-be-connectedstructure, and thereby self-alignment between a layer of theto-be-connected structure and a layer where the contact hole is arrangedis implemented. Only the region in which the imaging regions of the twoexposures overlap corresponds to the to-be-connected structure, whichimproves accuracy of the alignment between different layers and reducesthe error of the alignment.

In order to facilitate understanding technical solutions and technicaleffects of the present disclosure, hereinafter embodiments are describedin detail in conjunction with the drawings.

Reference is made to FIG. 1 , which is a flowchart of a method formanufacturing a semiconductor device according to an embodiment of thepresent disclosure. In this embodiment, a semiconductor device 100includes a substrate 110 and a to-be-connected structure 120 disposed ona side of the substrate 110. Reference is made to FIG. 2 and FIG. 3 .FIG. 2 is atop view of a structure of a semiconductor device 100according to an embodiment of the present disclosure, and FIG. 3 is across-sectional view along a direction indicated by AA, of thesemiconductor device as shown in FIG. 2 . In this embodiment, theto-be-connected structure 120 may be at least one of a gate structure, asource structure, or a drain structure. The to-be-connected structure120 may be made of a metal material having good conductivity. In anotherembodiment, the to-be-connected structure may be a structure in a layerserving as a target of alignment.

In one embodiment, the substrate 110 is a semiconductor substrate, suchas a Si substrate, a Ge substrate, a SiGe substrate, an SOI (silicon oninsulator) substrate, or a GOI (germanium on insulator) substrate. Inanother embodiment, the semiconductor substrate may be a substrateincluding another elementary semiconductor or another compoundsemiconductor, such as quartz, GaAs, InP, or SiC. The semiconductorsubstrate may alternatively be a stacked structure such as Si/SiGe, oranother epitaxial structure such as SGOI (silicon-germanium oninsulator). In this embodiment, the substrate 110 is a siliconsubstrate.

In practical applications, another film may be formed between thesubstrate 110 and the to-be-connected structure 120, so as to formvarious semiconductor devices.

As an example, stacked layers and a channel structure running throughthe stacked layers are formed between the substrate 110 and theto-be-connected structure 120. In such case, the semiconductor devicemay be a three-dimensional memory device.

As another example, a doped layer or another dielectric film is formedbetween the substrate 110 and the to-be-connected structure 120. In suchcase, the semiconductor device may be a logic device, such as atransistor.

The method includes the following steps S101 to S103.

In step S101, a photolithographic coating 130 is formed on theto-be-connected structure 120. Reference is made to FIG. 4 .

In embodiments of the present disclosure, the photolithographic coating130 is formed on the to-be-connected structure 120. Thephotolithographic coating 130 is patterned, such that a metal contact isformed through the patterned photolithographic coating 130, and theto-be-connected structure 130 is electrically connected to outside (ledout) via the metal contact.

In practical applications, before the photolithographic coating 130 isformed on the to-be-connected structure 120, a dielectric layer 140 isfirst formed on the to-be-connected structure 120. That is, thedielectric layer 140 is disposed between the to-be-connected structure120 and the photolithographic coating 130, as shown in FIG. 4 . Thedielectric layer 140 may be made of a material with good insulation,such as silicon oxide. The dielectric layer 140 may be formed bydepositing a dielectric material through deposition techniques. When thedielectric material is deposited on the to-be-connected structure 120,the formed dielectric layer 140 is conformal with the to-be-connectedstructure 120, so that morphology of the dielectric layer 140 is similarto that of the to-be-connected structure 120. In such case, thedielectric layer 140 may be ground by a device for chemical mechanicalgrinding. Hence, the obtained dielectric layer 140 has high flatness,and the photolithographic coating 130 can be formed on the flatdielectric layer 140 in a subsequent step.

In embodiments of the present disclosure, the photolithographic coating130 includes a first film 131, a photolithographic film 132, and asecond film 133 that are stacked in the above-listed sequence.Refractive indexes of the first film 131 and the second film 132 aresmaller than 1. An optical structure of the photolithographic coating130 including the first film 131, the photolithographic film 132, andthe second film 133 is similar to a sandwich. Two outer layers of thephotolithographic coating are films each having a refractive indexsmaller than 1. An incident light is reflected and oscillates in thephotolithographic coating 130, and hence intensity of the incident lightis enhanced by the reflection and the oscillation.

The photolithographic film 132 is made of a photoresist. Each of thefirst film 131 and the second film 133 may be made of a metal materialor a metamaterial. The metal material may be, for example, gold, silver,or copper, which has a refractive index smaller than 1 for adeep-ultraviolet, visible, or infrared light. The metamaterial may be acombination of some compound materials and certain materials. Themetamaterial may be synthetic to achieve the refractive index smallerthan 1 for light having a certain wavelength.

In practical application, the first film 131, the photolithographic film132, and the second film 133, which are sequentially stacked, may beformed through spin coating techniques, deposition techniques, or ionsputtering techniques. The first film 131, the photolithographic film132, and the second film 133 may be ground by a device for chemicalmechanical grinding, to control flatness and thicknesses of the firstfilm 131, the photolithographic film 132, and the second film 133,respectively.

In step S102, the photolithographic coating 130 is exposed to a lighthaving a first wavelength. Reference is made to FIG. 5 .

In embodiments of the present disclosure, the photolithographic coating130 may be exposed through photolithography techniques, after thephotolithographic coating 130 is formed on the to-be-connected structure120.

The photolithographic coating 130 is first exposed to the light havingthe first wavelength. In the exposure, the photolithographic coating 130is directly irradiated by a collimated light, and there is no mask. Thephotolithographic coating 130 provides high reflectivity for the lighthaving the first wavelength, and the to-be-connected structure 120 underthe photolithographic coating 130 can be imaged to a first region 132-1of the photolithographic film 132, as shown in FIG. 5 . That is, whenthe photolithographic coating 130 is exposed to the light having thefirst wavelength, the to-be-connected structure 120 is equivalent to amask, and the light having the first wavelength induces a photo-chemicalreaction in the first region 132-1 to image the to-be-connectedstructure 120 to the photolithographic film 132.

In embodiments of the present disclosure, thicknesses of the first film131, the photolithographic film 132, and the second film 133 in thephotolithographic coating 130 may be obtained through simulation insoftware. Generally, a thickness of the photolithographic film 132 isgreater than thicknesses of the first film 131 and the second film 133.The thickness of the photolithographic film 132 affects an intensity ofthe light in the photolithographic film 132, during the exposure withthe light having the first wavelength.

Reference is made to FIG. 6 , which is a schematic diagram showingcorrespondence between the thickness of the photolithographic film andthe intensity of the light according to an embodiment of the presentdisclosure. As can be seen from FIG. 6 , the intensity of the lighthaving the first wavelength changes in the photolithographic film 132along with the thickness of the photolithographic film 132. In thisembodiment, a thickness of the photolithographic film 132 may beselected in correspondence to a case in which the light having the firstwavelength in the photolithographic film 132 has maximum intensity, sothat the to-be-connected structure 120 is imaged to thephotolithographic film 132 with maximum efficiency.

In step S103, the photolithographic coating 130 is exposed to a lighthaving a second wavelength through a mask 150. Reference is made to FIG.7 .

In embodiments of the present disclosure, the photolithographic coating130 may be further exposed to the light having the second wavelengththrough the mask 150, after being subject to the exposure with the lighthaving the first wavelength. The to-be-connected structure 120 would notbe reflected in the photolithographic film 132, after the light havingthe second wavelength strikes on the photolithographic coating 130. Thatis, the light having the second wavelength does not image theto-be-connected structure 120 to the photolithographic film 132.

In other words, the light having the second wavelength images only apattern of the mask 150 to the second region 132-2 of thephotolithographic film 132, and does not image the to-be-connectedstructure 120 to the photolithographic film 132. The light having thesecond wavelength induces a photo-chemical reaction in the second region132-2, and thereby images the pattern of the mask 150 to thephotolithographic film 132.

In embodiments of the present disclosure, the photolithographic film 132has an optical response to both the light having the first wavelengthand the light having the second wavelength. When the photolithographicfilm is first exposed to the light having the first wavelength, aphotochemical reaction occurs in the first region 132-1 of thephotolithographic film 132, and hence a position of the to-be-connectedstructure 120 is determined. When the photolithographic film is thenexposed to the light having the second wavelength, a photochemicalreaction occurs in the second region 132-2 of the photolithographic film132, and hence a position of a contact hole is determined. Photochemicalreactions occur in both exposures in a region in which the first region132-1 and the second region 132-2 overlap, and such region serves as aconnection region corresponding to the to-be-connected structure 120.

In other words, only the region in which imaging regions of the twoexposures overlap in the photolithographic film is considered tocorrespond to the to-be-connected structure. Only the photolithographicfilm in the connection region would be developed through developmenttechniques in a subsequent step. The other part of photolithographicfilm, in which only one photochemical reaction occurs or nophotochemical reaction occurs, would not be developed. Thereby, achievedis self-alignment between a layer of the to-be-connected structure and alayer in which the contact hole is located, improving accuracy ofalignment between different layers and reducing an error of thealignment.

In embodiments of the present disclosure, the light having the firstwavelength is capable to image the to-be-connected structure 120 to thephotolithographic film 132, and the light having the second wavelengthis capable to image the pattern of the mask 150 to the photolithographicfilm 132. For example, the light having the first wavelength may be avisible light or an ultraviolet light, and the light having the secondwavelength may be an ultraviolet light or a visible light. In a casethat the second wavelength is smaller than the first wavelength, thepattern of the mask is imaged with higher resolution, and the positionof the contact hole is determined more accurately, which facilitates theself-alignment between the layer of the to-be-connected structure andthe layer in which the contact hole is arranged. In a case that thefirst wavelength is smaller than the second wavelength, a fine structureof the to-be-connected structure is reflected in the photolithographicfilm with high precision, which facilitates increasing a margin foralignment and overlay of the mask and reducing a mask error factor.

As an example, the first wavelength is 633 nm or 532 nm, and the secondwavelength is 365 nm, 248 nm, or 193 nm.

As another example, the first wavelength is 365 nm, 248 nm, or 193 nm,and the second wavelength is 532 nm or 633 nm.

In an embodiment, reference is made to FIG. 8 , which is a schematic topview of a semiconductor device and a mask according to an embodiment ofthe present disclosure. FIG. 7 is a cross-sectional view of thesemiconductor device and the mask as shown in FIG. 8 along a directionindicated by BB. A position at which the pattern of the mask 150 isexposed is located in the first region 132-1 of the photolithographicfilm 132, and a feature size of the pattern of the mask 150 is largerthan that of the to-be-connected structure 120, as shown in FIG. 8 . Anexposure size of the pattern of the mask 150 is S, a feature size of theto-be-connected structure 120 is M. and S is greater than M. Even if acenter of the pattern of the mask 150 deviates from a center of theto-be-connected structure 120, an overlapping region between the patternof the mask 150 and the to-be-connected structure 120 can still beensured to have a maximum area, hence achieving self-alignment.

As shown in FIG. 8 , the pattern of the mask may be consistent with ashape of a hole, so as to form a contact hole in a subsequent step. Themask may be a binary mask or an attenuated phase shift mask. A substrateof the mask may be made of quartz or other non-opaque material. Anopaque part of the mask may be formed by a metal material such aschromium.

In embodiments of the present disclosure, when the mask 150 is imaged bythe light having the second wavelength in the photolithographic film130, the photochemical reactions or the developing techniques arecontrolled, such that only a region irradiated by both the light havingthe second wavelength and the light having the first wavelength issubject to a secondary photo-chemical reaction and then developed in asubsequent step. The region irradiated by both the light having thesecond wavelength and the light having the first wavelength serves asthe connection region 1001.

In embodiments of the present disclosure, the photolithographic film 132in a certain region may be modified through laser heating and lasercuring, such that the certain region is hard to form an image with thelight having the second wavelength. The certain region may be a regionother than the first region 132-1.

In embodiments of the present disclosure, the second film 133 may beremoved after the second exposure of the photolithographic coating 130,to facilitate developing the photolithographic film 132 to form apatterned photolithographic film 160. Reference is made to FIG. 9 .After the development, the photolithographic film 132 corresponding tothe connection region 1001 is removed.

Afterwards, the dielectric layer 140 corresponding to the connectionregion 1001 is etched through the patterned photolithographic film 160,to obtain a contact hole 170 running through the dielectric layer 140.Thereby, the to-be-connected structure 120 is exposed by the contacthole 170, as shown in FIG. 10 . The first film 131 is also etched whenthe dielectric layer is etched through the patterned photolithographicfilm 160. After the contact hole 170 running through the dielectriclayer 140 is obtained, the remaining photolithographic film 160 and theremaining first film 131 are removed, and only the dielectric layer 140having the contact hole 170 is retained.

After the contact hole 170 is formed at a position corresponding to theto-be-connected structure 120, a metal material is filled in the contacthole 170 to form a metal contact 180. The metal contact 180 is connectedwith the to-be-connected structure 120, that is, the to-be-connectedstructure 120 is electrically connected to outside, as shown in FIG. 11.

In embodiments of the present disclosure, the photolithographytechniques for forming the metal contact may be extreme ultravioletphotolithography techniques, deep ultraviolet photolithographytechniques, nanometer imprinting techniques, super diffractionphotolithography techniques, or other techniques utilizing opticalimaging.

The method for manufacturing the semiconductor device is providedaccording to embodiments of the present disclosure. The semiconductordevice includes the substrate and the to-be-connected structure disposedon the side of the substrate. The photolithographic coating is formed onthe to-be-connected structure. The photolithographic coating includesthe first film, the photolithographic film, and the second film, whichare stacked in the above-listed sequence. The refractive indexes of thefirst film and the second film are smaller than 1, so that thephotolithographic coating forms an optical structure with a highreflection coefficient. Then, the photolithographic coating is exposedto the light having the first wavelength. The to-be-connected structureis reflected in the photolithographic coating, and hence serves as amask and is imaged to the first region of the photolithographic film.

Afterwards, the photolithographic coating is exposed to the light havingthe second wavelength through the mask. The mask is imaged to the secondregion of the photolithographic film. The region in which the firstregion and the second region overlap serves as the connection regioncorresponding to the to-be-connected structure. That is, positions atthe to-be-connected structure are imaged into the first region of thephotolithographic film after the exposure with the light having thefirst wavelength, and the pattern of the mask is imaged to the secondregion of the photolithographic film after the exposure with the lighthaving the second wavelength. The region in which the first regionoverlaps the second region corresponds to the to-be-connected structure,and thereby self-alignment between a layer of the to-be-connectedstructure and a layer where the contact hole is arranged is implemented.Only the region in which the imaging regions of the two exposuresoverlap corresponds to the to-be-connected structure, which improvesaccuracy of the alignment between different layers and reduces the errorof the alignment.

The embodiments of the present disclosure are described in a progressivemanner, and each embodiment places emphasis on the difference from otherembodiments. Therefore, one embodiment can refer to other embodimentsfor the same or similar parts. Since apparatuses disclosed in theembodiments correspond to methods disclosed in the embodiments, thedescription of the apparatuses is simple, and reference may be made tothe relevant part of the methods.

The foregoing embodiments are only preferred embodiments of the presentdisclosure. The preferred embodiments according to the disclosure aredisclosed above, and are not intended to limit the present disclosure.With the method and technical content disclosed above, those skilled inthe art can make some variations and improvements to the technicalsolutions of the present disclosure, or make some equivalent variationson the embodiments without departing from the scope of technicalsolutions of the present disclosure. All simple modifications,equivalent variations and improvements made based on the technicalessence of the present disclosure without departing the content of thetechnical solutions of the present disclosure fall within the protectionscope of the technical solutions of the present disclosure.

1. A method for manufacturing a semiconductor device, wherein: thesemiconductor device comprises a substrate and a to-be-connectedstructure disposed on a side of the substrate; and the method comprises:forming a photolithographic coating on the to-be-connected structure,wherein the photolithographic coating comprises a first film, aphotolithographic film, and a second film which are stacked in theabove-listed sequence, and refractive indexes of the first film and thesecond film are smaller than 1; exposing the photolithographic coatingto a light having a first wavelength, to image the to-be-connectedstructure to a first region of the photolithographic film; exposing thephotolithographic coating to a light having a second wavelength througha mask, to image a pattern of the mask to a second region of thephotolithographic film; and forming an electrical connection in contactwith the to-be-connected structure at a connection region, wherein theconnection region is a region in which the first region and the secondregion overlap.
 2. The method according to claim 1, wherein beforeforming the photolithographic coating on the to-be-connected structure,the method further comprises: determining a thickness of thephotolithographic coating based on simulated light intensity, which inthe photolithographic film when the photolithographic coating is exposedto the light having the first wavelength.
 3. The method according toclaim 1, wherein: before forming the photolithographic coating on theto-be-connected structure, the method further comprises: forming adielectric layer on the to-be-connected structure, wherein thedielectric layer is disposed between the to-be-connected structure andthe photolithographic coating; and after exposing the photolithographiccoating to the light having the second wavelength through the mask, themethod further comprises: etching the dielectric layer corresponding tothe connection region through the photolithographic film, to obtain acontact hole running through the dielectric layer, wherein theto-be-connected structure is exposed by the contact hole.
 4. The methodaccording to claim 3, wherein before etching the dielectric layercorresponding to the connection region through the photolithographicfilm, the method further comprises: removing the second film.
 5. Themethod according to claim 3, wherein after etching the dielectric layercorresponding to the connection region through the photolithographicfilm to obtain the contact hole running through the dielectric layer,the method further comprises: filling the contact hole with metal toform a metal contact, wherein the metal contact is connected with theto-be-connected structure.
 6. The method according to claim 1, whereinthe photolithographic film is made of a photoresist, and the first filmand the second film are made of metal materials.
 7. The method accordingto claim 1, wherein the light having the first wavelength is a visiblelight or an ultraviolet light, and the light having the secondwavelength is another ultraviolet light.
 8. The method according toclaim 7, wherein the first wavelength is 633 nm, 532 nm, or 365 nm, andthe second wavelength is 365 nm, 248 nm, or 193 nm.
 9. The methodaccording to claim 1, wherein the to-be-connected structure is at leastone of: a gate structure, a source structure, or a drain structure. 10.The method according to claim 1, wherein a feature size of the patternof the mask is larger than a feature size of the to-be-connectedstructure.